The subject of the present application is a dyeing composition for dyeing keratinous fibres, in particular human keratinous fibres such as hair, comprising, in an appropriate dyeing medium, at least one cationic tertiary para-phenylenediamine containing a pyrrolidine ring, and at least one cationic direct dye comprising at least one heterocycle group.
The subject of the invention is also the use of this composition for dyeing keratinous fibres and the dyeing method using this composition.
It is known to dye keratinous fibres, and in particular human hair, with dyeing compositions containing oxidation dye precursors, generally called oxidation bases, such as ortho- or para-phenylenediamines, or ortho- or para-aminophenols and heterocyclic compounds. These oxidation bases are colourless or weakly coloured compounds which, when combined with oxidizing products, can give rise, through a process of oxidative condensation, to coloured compounds.
It is also known that it is possible to vary the shades obtained with these oxidation bases by combining them with couplers or colour modifiers, the latter being chosen in particular from aromatic meta-diamines, meta-aminophenols, meta-diphenols and certain heterocyclic compounds such as indole compounds.
The variety of molecules used in the oxidation bases and couplers allows a rich palette of colours to be obtained.
The so-called “permanent” coloration obtained using these oxidation dyes should moreover satisfy a number of requirements. Thus, it should be without disadvantage from the toxicological point of view, it should make it possible to obtain shades in the desired intensity and should exhibit good fastness to external agents such as light, adverse weather conditions, washing, permanent waving, perspiration and rubbing.
The dyes should also make it possible to cover grey hair, and should finally be as less selective as possible, that is to say it is possible to obtain the least possible colour variations along the length of the same keratinous fibre, which is in general differentially sensitized (that is to say damaged) between its tip and its root.
It has already been proposed, in patent application WO 02/45675, to use compositions for the oxidation dyeing of keratinous fibres comprising a cationic tertiary para-phenylenediamine containing a pyrrolidine ring.
These cationic tertiary para-phenylenediamines containing a pyrrolidine ring lead to compositions which exhibit a harmlessness which is generally considered better than the compositions containing conventional para-phenylenediamines. However, the shades obtained when these compositions are used are markedly less intense and markedly more selective, that is to say that the dyes obtained exhibit substantial variations in colorations as a function of the degree of sensitization of the various types of hair or of the various areas of the same hair. The fastness of these shades can also vary greatly according to the degree of sensitization. In addition, the colorations obtained are also often more grey, that is to say less chromatic.